Filter sheet



FIG. 1 is a top plan view of a filter sheet showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a side elevational view thereof, the opposite side being identical;

FIG. 4 is a front elevational view thereof, the rear being identical; and,

FIG. 5 is a front elevational view thereof, on an enlarged scale, partially shown for clarity and ease of illustration. 

The ornamental design for a filter sheet, as shown and described. 